title: Effect of low-level laser therapy (808 nm) in skeletal muscle after resistance exercise training in rats.
abstract: OBJECTIVE
  The aim of this study was to evaluate the effects of 808 nm laser applied after a resistance training protocol, on biochemical markers and the morphology of skeletal muscle in rats.
  
  
  BACKGROUND
  Strenuous physical activity results in fatigue and decreased muscle strength, impaired motor control, and muscle pain. Many biochemical and biophysical interventions have been studied in an attempt to accelerate the recovery process of muscle fatigue. Among these, low-level laser therapy (LLLT) has been demonstrated to be effective in increasing skeletal muscle performance in in vivo studies and in clinical trials. However, little is known about the effects of LLLT on muscle performance after resistance training.
  
  
  METHODS
  Thirty Wistar rats were randomly divided into three groups: control group (CG), trained group (TG), and trained and laser-irradiated group (TGL). The resistance training program was performed three times per week for 5 weeks, and consisted of a climbing exercise, with weights attached to the tail of the animal. Furthermore, laser irradiation was performed in the middle region of tibialis anterior (TA) muscle of both legs, after the exercise protocol.
  
  
  RESULTS
  Analysis demonstrated that TGL demonstrated significantly reduced resting lactate level and decreased muscle glycogen depletion than the animals that were exercised only, and significantly increased the cross-section area of TA muscle fibers compared with thoseo in the other groups.
  
  
  CONCLUSIONS
  These results suggest that LLLT could be an effective therapeutic approach in increasing muscle performance during a resistance exercise protocol.
authors.affiliation: 1 Department of Physiotherapy, Federal University of São Carlos , São Carlos, São Paulo, Brazil .
authors.forename: Tatiane
authors.initials: T
authors.lastname: Patrocinio
authors.forename: Andre Cabral
authors.initials: AC
authors.lastname: Sardim
authors.forename: Livia
authors.initials: L
authors.lastname: Assis
authors.forename: Kelly Rossetti
authors.initials: KR
authors.lastname: Fernandes
authors.forename: Natalia
authors.initials: N
authors.lastname: Rodrigues
authors.forename: Ana Claudia Muniz
authors.initials: AC
authors.lastname: Renno
mesh_terms: D000818:Animals; D006003:Glycogen / Q000378:metabolism; D007773:Lactates / Q000097:blood; D028022:Low-Level Light Therapy; D008297:Male; D018482:Muscle, Skeletal / Q000502:physiology / Q000528:radiation effects*; D010805:Physical Conditioning, Animal; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar
chemical_list: D007773:Lactates; D006003:Glycogen